Device for servicing refrigeration systems

ABSTRACT

A device for servicing refrigeration systems of refrigerators and air conditioners, which involves the use of a novel coupling facilitating connection of testing or refilling equipment to the liquid refrigerant supply line and the suction line in the system, without escape of refrigerant.

iihiie iieh hiehi Maw/11111110 51 i eh, 20, 11972 [54] UEVIUCIE iFUiiiSEIRWHCHWG 2,765,806 10/1956 Webster ..137/322 REEFHGERATHQN sys'mmg1,703,311 2/1929 Lit1e,Jr. ..62/299 1,830,894 11/1931 Ullstrand et :11......137/319 X [721 lnvenm" W gwg 25 indla" all, 2,614,400 10/1952 May..62/292 3,424,181 1/1969 Morse ..62/292 x [22] Filed: Apr. 117, 1970Primary Examiner-William R. Cline [211 App! ZWEM Attorney-J-iill,Sherman, Meroni,Gross&Simpson [52] U.S.Cl ..2S11/11 l0,251/291, 137/322,[57] AES'llliM/C'll '2 292 [51 11m. 01 .10161131/50 1 2512 42700 Adevice for Servicing refrigeram" systems ref'ige'amm [5s] 1 1E111(BitBfi1rciIi..........,.....:.25 1/148 151 15 2 291 292 and "ditimers,which WIVES a 251/215; 137/317, 319, 320, 32 2, 22 8, 229; 62 /292:coupling facilitating connection of testing or refilling equip- 9 2 9ment to the liquid refrigerant supply line and the suction line in thesystem, without escape of refrigerant. [56] lheierences Cited 5 Claims,3 Drawing Figures DiEl/HUE FUR SIEIRVICHNG REIFMGIERATHUN SYSTEMS Thisinvention relates to the art of servicing refrigeration systemsutilizing compressible evaporative fluid refrigerant, and is moreparticularly concerned with a device by which such servicing isfacilitated.

As referred to herein refrigeration system is intended to mean anysystem in which a compressible evaporative fluid is employed to removeheat from an enclosed space, including without limitation refrigeratorsfor preserving perishables and air conditioners. In the servicing ofsuch systems, it becomes necessary to test the refrigerant line pressureand also to supply the line with additional or makeup refrigerant ifnecessary. For this purpose, the refrigerant lines may be equipped withone or more access connections having nipples to which testing or supplylines are adapted to be coupled and which are equipped with normallyclosed, depressibly operable valves. In the course of attaching thetesting or supply lines to or removing them from such connections it hasheretofore been common experience that substantial volume of refrigerantwould escape as a result of depressing and opening of the respectivevalves during attachment and before the couplings could be tightened,and during detachment before the couplings could be removed. In additionto disadvantages of refrigerant loss, the escaping refrigerant produceda dangerous environmental condition with liability of injury toservicemens hands due to contact with the couplings chilled to belowfreezing temperature, or due to direct impingement by the escapingrefrigerant gas or liquid.

According to the present invention the foregoing and otherdisadvantages, shortcomings, difliculties, inefficiencies and problemsare overcome by providing a new and improved device for servicingrefrigeration systems efficiently without detrimental refrigerant lossand with perfect safety.

An object of the invention is to provide a new and improved device forservicing refrigeration systems without loss of refrigerant.

A further object of the invention is to provide new and improved meansin servicing equipment for refrigeration systems enabling attachment ofservicing lines without loss of refrigerant.

Still another object of the invention is to provide new and improvedsafety coupling means for safely and efficiently connecting a servicingline such as a testing line or a refrigerant supply line to arefrigeration system having a connection pro vided with a depressiblenormally closed valve.

Other objects, features and advantages of the invention will be readilyapparent from the following description of a preferred embodimentthereof, taken in conjunction with the accompanying drawing, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

FlG. l is a schematic illustration of a refrigeration system andservicing equipment;

FIG. 2 is an enlarged vertical sectional detail view through a safetycoupling device embodying features of the invention and employed inconnecting the test equipment to the refrigeration system; and

FIG. 3 is a side elevational view of the safety coupling showing thesame in idle condition.

On reference to FIG. l a refrigeration system is schematically depictedin which an evaporator 5 is operatively connected through a liquidrefrigerant supply line or duct 7 and a gaseous refrigerant return orsuction line or conduit 8 with a compressor and condenser assembly (notshown) within a housing 9. This provides a closed circuit in which aliquifiable and evaporable refrigerant such as F room is circulatedthrough the evaporator in a well-known manner. Inasmuch as such arefrigeration system must be maintained in a fairly delicate balance forhighest efficiency, it is advisable to test the system from time to timeto determine that the charge of refrigerant is in proper volume asreflected by pressure in the liquid supply line. If there appears to beneed for replenishing or augment ing the refrigerant charge, additionalrefrigerant is then delivered to the system from a supply source.

To enable a Serviceman to test and supply the refrigeration systemconveniently a portable apparatus may be used including a manifold Mlmounting a line pressure testing gauge ll adjacent to a valve having ahandle 12 and adapted to be placed in communication with the liquidrefrigerant duct 7 by means of a connecting line or duct 113. Means arealso provided by the manifold M for recharging or supplying makeuprefrigerant to the refrigeration system, and comprising a duct 14connected to or arranged to be connected to a liquid refrigerant supplycontainer I5 and communicating through the manifold l0 and past apressure gauge 117 and under the control of a valve operated by a handle118 with a refrigerant supply duct 19 adapted for connection with therefrigeration system and more particularly the suction duct 8 thereof.

According to the present invention, a respective safety coupling 2b isprovided for connecting each of the pressure testing duct 17 and thesupply duct 19 with the respective refrigeration system ducts 7 and 8.As best seen in FIG. 2, each of the couplings 20 comprises a body 21having thereon an externally threaded nipple 22 which has a bore 23adapted to be placed in liquid flow communication with a flared tubularmetal terminal 24 of the duct 13 or 119, as the case may be, detachablysecured in fluidtight relation to the nipple by means of a coupling nut25.

Also carried by the body 211 are means for effecting communication witha valved access nipple 27 extending from the respective fitting of therefrigerant line 7 or the suction line 8, and more particularly thefitting by which such line is connected to the compressor/condenser unitwithin the housing 9. Escape of refrigerant from within the fittingthrough the nipple 27 is normally prevented by a check valve 28 which isnormally spring biased outwardly into closing relation to a generallyinwardly facing valve seat 29 and has an outwardly extending rod or stem30 which is adapted to be depressed in-. wardly to unseat the valve whendesired. Externally the nipple 27 is threaded to be received within acoupling nut 3ll rotatably engaged upon a shouldered tubular baseextension 32 having recessed into its outer end a sealing gasket or ring33 which effects a sealed joint between the end of the nipple 27 and thebase 32 when the nut 31 is threaded onto the nipple and draws the basetightly toward the end of the nipple. To facilitate both manual andwrench manipulation of the nut 3i, it is desirably provided with anannular knurled surface area 34 and a wrench face area 35. To facilitateassembly, the base 32 is desirably formed separate from the body 21 andpro vided with a reduced diameter tubular extension 37 secured as bymeans of brazing into a bore 38 in the body with the inner end of theextension opening into and effecting communication between a bore 39therein and the bore 23. Through this arrangement, the coupling assembly20 is adapted to effect a sealed communicating connection between theassociated refrigerant line terminal 24 and fitting nipple 27.

In order to enable the coupling assembly 20 to be operated to tap theassociated refrigerant line, means are provided including a manuallyoperable depressor comprising a plunger 39a of smaller diameter than andextending reciprocably coaxially in the bore 39 in alignment with thevalve stem 30 when the coupling has been attached to the nipple 27. Formoving the plunger 39a between valve stem depressing and inactivepositions within the coupling assembly, it is preferably constructed andarranged as a rigid inward extension from a rotary shaft 430 having athreaded area 41 operatively engaged within a tapped bore 42 of atubular extension 43 on the body 21 coaxially aligned with the baseextension 37. By turning the shaft 41h as by means of a handwheel ormanipulating head 44 on its outer end, the shaft and thereby the plunger39a can be run inwardly or outwardly relative to the coupling body.Leakage past the shaft is prevented by means of a packing 45 compressedthereabout and against the outer end of the extension 43 by a packingnut 47 screwed onto external threads of this extension.

To facilitate assembly and operation, the shaft an is of substantiallylarger diameter than the plunger 39a, and a stepped juncture face 48 ispresent where they join. This juncture 48 faces toward and is amplyseparated from an inner end face 49 on the base extension 37 about theopening from the bore 39 and through which the plunger 39a extends toassure free flow of refrigerant past the gap between the faces 48 and 49when the plunger is operated to open the valve 28.

Inasmuch as the test lines 13 and 19 may have to be connected torefrigeration system lines that are not equipped with depressible stemvalves, and it is highly desirable to maintain the interior of thecoupling assembly 20 perfectly clean and avoid any foreign mattergetting thereinto when it is not in use on the respective test line, theopposite ends of the passage through the coupling assembly should beclosed. For this purpose, as best seen in FIG. 3, the coupling assembly20 is provided with a screw-on closure cap 50 removably threaded ontothe coupling nipple 22. In addition, a screw-in plug 51 is desirablyremovably threadedly engaged in the coupling nut 31 and may be drivenagainst the sealing ring 33 to maintain perfect closure. In fact, theplug 51 may be used to close the opening into the coupling assemblythrough the nut 31 during inactive condition of the coupling assemblyeven though it remains attached to the selected test equipment conduit13 or 19.

Assuming that it is desired to test and, if necessary, replenish therefrigeration system, the respective coupling assemblies 20 are preparedfor attachment to the nipples 27 by attaching them to the respectivetest lines 13 and 19, by removing the respective plugs 50 and 51, bybacking off the depressor plunger 39:: in each instance to be sure therespective valves 28 will not be prematurely opened, and attaching thecoupling assemblies to the selected nipples 27 by means of the couplingnuts 31. After the coupling nut 20 has been attached in fluidtightrelation to the liquid refrigerant line 7, the depressor plunger 39a isoperated to depress and open the valve 28, whereupon pressure in theliquid refrigerant line 7 is 7 adapted to be tested by operation of thegauge 11. Should it be necessary to replenish the refrigeration system,the coupling assembly 20 associated with the equipment line 19 isadapted to be operated similarly as already described, and replenishmenteffected through such line from the refrigerant supply 15. After testingand replenishment have been completed, the plungers 39a are backed offto close the respective valves 28 to avoid any loss of refrigerant fromthe system, and the testing equipment removed. This assures that thefinal system pressure as revealed by the test pressure gauge or gaugeswill remain true after the testing equipment couplings 20 are removed.Before use on another system the test lines 13 and 19, or at least theline 13, are desirably purged by manipulating the valves in the manifoldwhile the refrigerant supply is connected.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

I claim as my invention:

1. In a coupling for refrigeration system testing or refrigerantreplenishing equipment of the kind including a pressure gauge and a ductconnected therewith to communicate with a refrigerant line in saidsystem through an access nipple having a normally closed valve whichmust be depressed to open:

a coupling body having a passage therein with openings at opposite ends;

means for connecting one end of said passage in communication with saidduct;

means for connecting the opposite end of said passage in operativecommunication with said nipple;

means operable selectively after both ends of said passage have beenconnected as aforesaid to depress and open said valve;

and comprising a plunger aligned with said opposite end and means foroperating said plunger;

said plunger being fixed coaxially on one end of a rotary shaft whichhas its opposite end portion projecting from said body and has amanipulating head thereon comprising said means for operating theplunger;

said body and said shaft having interengaging threaded means foreffecting reciprocal movements of said shaft and thereby said plunger byrotation of said shaft by manipulation of said head;

a nipple providing said means for connecting to the duct;

a cap for closing said nipple when free from the duct;

said means for connecting the opposite end of the passage comprising anextension on said body carrying a rotary coupling nut;

and a threaded closure plug engageable in said nut;

whereby the interior of the coupling is maintained clean and free fromforeign matter getting thereinto when the coupling is not in use.

2. In a coupling according to claim 1, said body extension having ashoulder within said coupling nut, a sealing ring on said shoulder, saidplug being drivable against said sealing ring to maintain a perfectclosure.

3. In a coupling for refrigeration system testing or refrigerantreplenishing equipment of the kind including a pressure gauge and a ductconnected therewith to communicate with a refrigerant line in saidsystem through an access nipple having a normally closed valve whichmust be depressed to open:

a coupling body having a passage therein with openings at opposite ends;

means for connecting one end of said passage in communication with saidduct;

means for connecting the opposite end of said passage in operativecommunication with said nipple;

means operable selectively after both ends of said passage have beenconnected as aforesaid to depress and open said valve;

and comprising a plunger aligned with said opposite end and means foroperating said plunger;

said plunger being fixed coaxially on one end of a rotary shaft whichhas its opposite end portion projecting from said body and has amanipulating head thereon comprising said means for operating theplunger;

said body and said shaft having interengaging threaded means foreffecting reciprocal movements of said shaft and thereby said plunger byrotation of said shaft by manipulation of said head;

and said body having a tubular base extension comprising a separatelyformed shouldered member carrying a rotary coupling nut engageable withsaid access nipple and having a tubular projecting portion engaged insaid body in alignment with said plunger and shaft, providing a part ofsaid passage and having said plunger extending thereinto.

4. In a coupling according to claim 3, said shaft being of substantiallylarger diameter than said plunger, said tubular base extension having abore of larger diameter than said plunger but of smaller diameter thansaid shaft and opening within said body toward said shaft, and saidshaft having a stepped shoulder which faces toward an inner end face ofsaid tubular base extension in spaced relation to assure free flow ofrefrigerant past the gap between the shoulder and face when the plungeris driven inwardly to open the normally closed valve.

5. In a coupling according to claim 3, a sealing ring recessed into theouter end of said extension to effect a sealed joint between the end ofthe nipple and the extension when the nut is threaded onto the nippleand draws the extension toward the end of the nipple.

1. In a coupling for refrigeration system testing or refrigerantreplenishing equipment of the kind including a pressure gauge and a ductconnected therewith to communicate with a refrigerant line in saidsystem through an access nipple having a normally closed valve whichmust be depressed to open: a coupling body having a passage therein withopenings at opposite ends; means for connecting one end of said passagein communication with said duct; means for connecting the opposite endof said passage in operative communication with said nipple; meansoperable selectively after both ends of said passage have been connectedas aforesaid to depress and open said valve; and comprising a plungeraligned with said opposite end and means for operating said plunger;said plunger being fixed coaxially on one end of a rotary shaft whichhas its opposite end portion projecting from said body and has amanipulating head thereon comprising said means for operating theplunger; said body and said shaft having interengaging threaded meansfor effecting reciprocal movements of said shaft and thereby saidplunger by rotation of said shaft by manipulation of said head; a nippleproviding said means for connecting to the duct; a cap for closing saidnipple when free from the duct; said means for connecting the oppositeend of the passage comprising an extension on said body carrying arotary coupling nut; and a threaded closure plug engageable in said nut;whereby the interior of the coupling is maintained clean and free fromforeign matter getting thereinto when the coupling is not in use.
 2. Ina coupling according to claim 1, said body extension having a shoulderwithin said coupling nut, a sealing ring on said shoulder, said plugbeing drivable against said sealing ring to maintain a perfect closure.3. In a coupling for refrigeration system testing or refrigerantreplenishing equipment of the kind including a pressure gauge and a ductconnected therewith to communicate with a refrigerant line in saidsystem through an access nipple having a normally closed valve whichmust be depressed to open: a coupling body having a passage therein withopenings at opposite ends; means for connecting one end of said passagein communication with said duct; means for connecting the opposite endof said passage in operative communication with said nipple; meansoperable selectively after both ends of said passage have been connectedas aforesaid to depress and open said valve; and comprising a plungeraligned with said opposite end and means for operating said plunger;said plunger being fixed coaxially on one end of a rotary shaft whichhas its opposite end portion projecting from said body and has amanipulating head thereon comprising said means for operating theplunger; said body and said shaft having interengaging threaded meansfor effecting reciprocal movements of said shaft and thereby saidplunger by rotation of said shaft by manipulation of said head; and saidbody having a tubular base extension comprising a separately formedshouldered member carrying a rotary coupling nut engageable with saidaccess nipple and having a tubular projecting portion engaged in saidbody in alignment with said plunger and shaft, providing a part of saidpassage and having said plunger extending thereinto.
 4. In a couplingaccording to claim 3, said shaft being of substantially larger diameterthan said plunger, said tubular base extension having a bore of largerdiameter than said plunger but of smaller diameter than said shaft andopening within said body toward said shaft, and said shaft having astepped shoulder which faces toward an inner end face of said tubularbase extension in spaced relation to assure free flow of refrigerantpast the gap between the shoulder and face when the plunger is driveninwardly to open the normally closed valve.
 5. In a coupling accordingto claim 3, a sealing ring recessed into the outer end of said extensionto effect a sealed joint between the end of the nipple and the extensionwhen the nut is threaded onto the nipple and draws the extension towardthe end of the nipple.